Femtosecond optical Kerr effect of PbS nanoparticles modification effect

The subpicosecond optical non-linearities of PbS nanoparticles modified by cetyltrimethylammonium bromide (CTAB) and sodium dodecyle benzene sulphonate (DBS) was synthesized and investigated by femtosecond optical Kerr effect (OKE) experiment. The non-linear optical effect (χ(3)/α for PbS(CTAB) and PbS(DBS), 2.6 × 10−13 and 8.4 × 10−14 esu cm, respectively) with the response time comparable to the laser pulser (∼165 fs) had been observed. The spectral behavior and the OKE results confirmed that the surface environment plays a crucial role on linear and non-linear optical properties.